clean-webpack-plugin

What is clean-webpack-plugin?

The clean-webpack-plugin is a plugin for webpack, a module bundler for JavaScript. It is used to remove/clean your build folder(s) before building. This ensures that only used files are generated when your project is built, preventing the accumulation of outdated files from previous builds.

What are clean-webpack-plugin's main functionalities?

Removing all files inside webpack's output.path directory

This feature automatically cleans up the output directory specified in webpack's configuration before each build, ensuring that only the files generated in the current build are present.

const { CleanWebpackPlugin } = require('clean-webpack-plugin');

module.exports = {
  plugins: [
    new CleanWebpackPlugin(),
  ],
};

Preserving specific files or directories during clean

This feature allows you to exclude specific files or directories from being deleted when the output directory is cleaned. This is useful for cases where you want to keep certain files across builds.

const { CleanWebpackPlugin } = require('clean-webpack-plugin');

module.exports = {
  plugins: [
    new CleanWebpackPlugin({
      cleanOnceBeforeBuildPatterns: ['**/*', '!static-files*'],
      cleanStaleWebpackAssets: false,
      protectWebpackAssets: false
    }),
  ],
};

Other packages similar to clean-webpack-plugin

rimraf

Rimraf is a deep deletion module for node (like `rm -rf`). It's not specifically tied to webpack but can be used in npm scripts or directly in node scripts to clean directories. It's simpler but requires manual configuration compared to clean-webpack-plugin's integration with webpack.

del

Del is another package for deleting files and directories. Similar to rimraf, it's used in build processes but isn't tied to webpack. It provides more control over what to delete through glob patterns and options but lacks the direct webpack integration that clean-webpack-plugin offers.

README

Clean plugin for webpack

A webpack plugin to remove/clean your build folder(s).

NOTE: Node v10+ and webpack v4+ are supported and tested.

About

By default, this plugin will remove all files inside webpack's output.path directory, as well as all unused webpack assets after every successful rebuild.

Coming from v1? Please read about additional v2 information.

Installation

npm install --save-dev clean-webpack-plugin

Usage

const { CleanWebpackPlugin } = require('clean-webpack-plugin');

const webpackConfig = {
    plugins: [
        /**
         * All files inside webpack's output.path directory will be removed once, but the
         * directory itself will not be. If using webpack 4+'s default configuration,
         * everything under <PROJECT_DIR>/dist/ will be removed.
         * Use cleanOnceBeforeBuildPatterns to override this behavior.
         *
         * During rebuilds, all webpack assets that are not used anymore
         * will be removed automatically.
         *
         * See `Options and Defaults` for information
         */
        new CleanWebpackPlugin(),
    ],
};

module.exports = webpackConfig;

Options and Defaults (Optional)

new CleanWebpackPlugin({
    // Simulate the removal of files
    //
    // default: false
    dry: true,

    // Write Logs to Console
    // (Always enabled when dry is true)
    //
    // default: false
    verbose: true,

    // Automatically remove all unused webpack assets on rebuild
    //
    // default: true
    cleanStaleWebpackAssets: false,

    // Do not allow removal of current webpack assets
    //
    // default: true
    protectWebpackAssets: false,

    // **WARNING**
    //
    // Notes for the below options:
    //
    // They are unsafe...so test initially with dry: true.
    //
    // Relative to webpack's output.path directory.
    // If outside of webpack's output.path directory,
    //    use full path. path.join(process.cwd(), 'build/**/*')
    //
    // These options extend del's pattern matching API.
    // See https://github.com/sindresorhus/del#patterns
    //    for pattern matching documentation

    // Removes files once prior to Webpack compilation
    //   Not included in rebuilds (watch mode)
    //
    // Use !negative patterns to exclude files
    //
    // default: ['**/*']
    cleanOnceBeforeBuildPatterns: [
        '**/*',
        '!static-files*',
        '!directoryToExclude/**',
    ],
    cleanOnceBeforeBuildPatterns: [], // disables cleanOnceBeforeBuildPatterns

    // Removes files after every build (including watch mode) that match this pattern.
    // Used for files that are not created directly by Webpack.
    //
    // Use !negative patterns to exclude files
    //
    // default: []
    cleanAfterEveryBuildPatterns: ['static*.*', '!static1.js'],

    // Allow clean patterns outside of process.cwd()
    //
    // requires dry option to be explicitly set
    //
    // default: false
    dangerouslyAllowCleanPatternsOutsideProject: true,
});

Example Webpack Config

This is a modified version of WebPack's Plugin documentation that includes the Clean Plugin.

const { CleanWebpackPlugin } = require('clean-webpack-plugin'); // installed via npm
const HtmlWebpackPlugin = require('html-webpack-plugin'); // installed via npm
const webpack = require('webpack'); // to access built-in plugins
const path = require('path');

module.exports = {
    entry: './path/to/my/entry/file.js',
    output: {
        /**
         * With zero configuration,
         *   clean-webpack-plugin will remove files inside the directory below
         */
        path: path.resolve(process.cwd(), 'dist'),
    },
    module: {
        rules: [
            {
                test: /\.(js|jsx)$/,
                loader: 'babel-loader',
            },
        ],
    },
    plugins: [
        new webpack.ProgressPlugin(),
        new CleanWebpackPlugin(),
        new HtmlWebpackPlugin({ template: './src/index.html' }),
    ],
};